Magnesium allyl complexes are regularly isolated with classical, sigma-bonded ligands, and this has been thought to be their preferred mode of bonding. Density functional theory calculations confirm that such bonding is the most stable mode when coordinated bases are present, but in their absence, pi-bonded forms are expected to be lower in energy. The isolation of the unsolvated [Mg{C(3)(SiMe(3))(2)H(3)}(2)](2) complex supports this prediction, as it is a dinuclear species in which two allyl ligands bridge the metals and display cation-pi interactions with them.
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http://dx.doi.org/10.1021/ja900998t | DOI Listing |
Angew Chem Int Ed Engl
January 2025
Shanghai Inst Org Chem, State Key Lab Organometallic Chem, 345 Lingling Lu, 200032, Shanghai, CHINA.
Rhodium-catalyzed regio- and enantioselective allylic arylation of racemic alkyl- and aryl- substituted allylic carbonates with arylboronic acids using commercially available BIBOP ligand is reported. This reaction proceeds at room temperature without base or other additive to deliver allylic arylation products in excellent yields, regio- and enantioselectivity (up to 95% yield, >20:1 b/l, >99% ee). Rh/BIBOP is disclosed as an efficient catalytic system for allylic substitution reaction.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
IISER Kolkata: Indian Institute of Science Education and Research Kolkata, Department of Chemical Sciences, Mohanpur, 741246, Nadia, INDIA.
Chiral allyl amines are important structural components in natural products, pharmaceuticals, and chiral catalysts. Herein, we report a cobalt-catalyzed enantioselective reductive coupling of imines with internal alkynes to synthesize chiral allyl amines. The reaction is catalyzed by a cobalt complex derived from commercially available bisphosphine ligand utilizing zinc as the electron donor.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
New Cornerstone Science Laboratory, State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Lu, Shanghai 200032, China.
The asymmetric Tsuji-Trost reaction has been extensively studied due to its importance in establishing stereogenic centers, often adjacent to an -olefin moiety in organic molecules. The generally preferential formation of chiral -olefin products is believed to result from the thermodynamically more stable -π-allylpalladium intermediate. The rapid associative π-σ-π isomerization makes it challenging to synthesize chiral -olefin products via the transient -π-allylpalladium intermediate.
View Article and Find Full Text PDFSci Bull (Beijing)
December 2024
State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200032, China. Electronic address:
Divergent synthesis of valuable molecules through common starting materials and metal catalysis represents a longstanding challenge and a significant research goal. We here describe chemodivergent, highly enantio- and regioselective nickel-catalyzed reductive and dehydrogenative coupling reactions of alkynes, aldehydes, and silanes. A single chiral Ni-based catalyst is leveraged to directly prepare three distinct enantioenriched products (silyl-protected trisubstituted chiral allylic alcohols, oxasilacyclopentenes, and silicon-stereogenic oxasilacyclopentenes) in a single chemical operation.
View Article and Find Full Text PDFEur J Med Chem
December 2024
A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, ul. Vavilova 28, bld. 1, Moscow, 119334, Russia. Electronic address:
Thevinols and their 3-O-demethylated relatives, orvinols, are derivatives of the Diels-Alder adduct of natural alkaloid thebaine with methyl vinyl ketone. Taken together, thevinols and orvinols constitute an important family of opioid receptor (OR) ligands playing an important role in both the OR mediated antinociception and OR antagonism. Herein, we disclose for the first time the antagonist activity of the N-allyl substituted orvinol derivative fluorinated within the pharmacophore associated with C(20) and its surrounding.
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